View Full Version : How long before the oxygen runs out?

12th Apr 2009, 20:55
I've always wondered why animals were so much larger in the past?

One theory is that oxygen was more plentiful in the time of the dinosaurs.

Given that oxygen levels must have decreased in the intervening period how long before the oxygen runs out, particularly in view of the unprecedented destruction of the environment in recent years?

Maybe bumble bees flew aerobatics in the past and are now reduced to lumbering aviators wheezing at the thought of flight?!



tony draper
12th Apr 2009, 21:03
Well let them breathe cake. :rolleyes:
Ere, there is a awful lot of it about,one suspects we talking monkeys will long be dust in the fossil record before oxygen runs out, if ever.
Something else occurs to me,read somewhere that if the percentage of oxygen in the atmosphere where just a tad higher we would probably all be killed by vast forest fires which once started would refuse to go out due due to the abundance of fire loving O,
Perhaps you have stumbled upon yet another reason for the demise of yon Dinosaurs.

12th Apr 2009, 21:11
Just in case, besides books and stamps that will constitute my dayly diet (I can digest cellulose, being an ant), I am accumulating oxygen tanks.
:} :}

12th Apr 2009, 21:22
The largest creature ever on the planet is the Blue Whale and it's still here.

It has obviously survived only by it's remarkable ability to hold its breath. :E

12th Apr 2009, 21:31
Wonder if mothr nature did us lot all over again, she would choose oxygen again.Terrible explosive corrosive nasty thing is oxygen. Personally, I only breath red wine.

tony draper
12th Apr 2009, 21:44
Well the Earth was totally devoid of Oxygen for the first billion years or so Oxygen was bye product of the first lifeforms, none oxygen breathing critters came first,then us,mommy natures first mistake perchance.
Stromatolites,these buggas kicked it all off.

green granite
12th Apr 2009, 22:10
Given that oxygen levels must have decreased in the intervening period how long before the oxygen runs out, particularly in view of the unprecedented destruction of the environment in recent years?

The destruction of the environment began several millennia ago when made ceased to be hunter gatherers and started farming.
when you consider that the whole of the UK was in effect forest
which has been cleared to facilitate agriculture modern environmental change is relatively insignificant.

12th Apr 2009, 22:52
Yep, if nature was intent on a chalcogen & had a weekend to think it over, she might have gone with Sulphur. No need for noses, lungs or an atmosphere. Just a hinged flap somewhere. Of course, we'd all live on Volcanoes & Lynx & Rightguard would rule the world. probably.

12th Apr 2009, 23:26
I was reading a little about this today, the history of atmospheric oxygen: The Great Oxidation Event (http://whyevolutionistrue.wordpress.com/2009/04/12/the-great-oxidation-event/). The oxygen wasn't always around, but now it's here, it's not about to go away. It can't escape in to space the way hydrogen and helium can - too heavy.

13th Apr 2009, 00:40
Very intersting that Bnt. Quite a thought that for the want of a lump or two of Nickel. we might all be looking very different. Nature clearly takes what's at hand & runs with it.

Impress to inflate
13th Apr 2009, 02:32
For gods sake, don't tell the government, they will start to tax it !!

tony draper
13th Apr 2009, 07:15
Maggie already tried that, it was called the Poll Tax.:)

Dan Winterland
13th Apr 2009, 08:09
Oxygen levels a hundred million years ago were about 32%. It is now about 21%. This is why land animals grew as big as they did and there were dragonflies the size of seagulls. Most of the oxygen has been absorbed into the earth through oxidization. The oxygen is still there, it's just locked up in compounds such as red coloured earth, for example. (Red earth = iron oxide).

13th Apr 2009, 09:21
Is that where we plant the green plants then ?
My dirt is gray/blackish, green plants seem to grow pretty well though.

Is there more oxygen in the big forrest in Brazil, compared to say downtown London, or does it move about fairly fast ?

Portable oxygen generators in backpacks ?

13th Apr 2009, 11:54
People can adapt to lower oxygen levels, if that's all that happens. Your lungs will work a bit harder, as they do at altitude. However, if the oxygen is replaced by some other gases, then we could have a problem. If you remember the Apollo 13 incident, the main threat to the astronauts was CO2 buildup, not the drop in O2.

13th Apr 2009, 12:53
Just think - if we can get rid of all the oxygen our cars won't go rusty!

They won't run either, so we can have everlasting cars.

13th Apr 2009, 12:59
There are many wishing to get rid of Co2, how long, if they have their way, before the planet ignites?

Yamagata ken
13th Apr 2009, 13:14
Your soil is grey/black because it is reduced and may be packed with oxidising organics (hence reducing the soil).

As the article quoted above states, before about 1.8 billion years ago, all the oxygen produced by photosynthesis was taken up by elements like iron and aluminium. Reduced iron is soluble, and the oceans were full of it. The banded iron formations are the sediment from a rain of iron oxide. When the reducing agents were exhausted, free oxygen was able to build in the atmosphere, giving us what we have now. It's lasted ~1.8 billion years, so I'm not holding my breath :8

Sidenote. The change from a methane to a nitrogen/oxygen atmosphere would have changed the Earth's climate dramatically (for the climate change sceptics). Not to be confused with "Global Warming", which is an entirely different thing.

Stromatolites in Shark Bay. Been there, done that.

13th Apr 2009, 17:29




Union Jack
13th Apr 2009, 17:34
Maggie already tried that, it was called the Poll Tax.http://static.pprune.org/images/smilies/smile.gif

One of your best ever, Mr Draper!:ok:


13th Apr 2009, 19:26
Maggie was a dragon anyhow.
Along a similar line to this "why were they so big?" thing.
Can anyone explain why so many of the early Biblical
people LIVED so long? What happened there then?
Perhaps the pension providers got all that altered!!
HOW old?? 650? B*gger that!!

13th Apr 2009, 19:47
When you find out how long we have left - even if it is just six months - please let us know so we can move in with our former spouses/partners.

It will be the longest six months of our lives.

13th Apr 2009, 22:55
With reference to long lived Biblical characters, apparently, in the old Russian Empire, there were many in the 'backwoods' areas who seemed to live for an extraordinary number of years. Turned out it was draft dodging - sons taking on parents ID in order to fool the recruiting officer that they were too old for the army.

Maybe, in a society where age conferred privilege something of the sort was going on?

13th Apr 2009, 23:20
Is this like um, Peak Oxygen?